Heretofore reserve pits of waste drilling fluids have been chemically treated and have had to lie dormant for several days or weeks while the solids under gravity clarification settle so that the liquid can be pumped off the top. Then the heavier solids are left in the pit for subsequent cleanup by other means. Such processes are shown in the two Virgil L. Dover U.S. Pat. Nos. 4,234,421 and 4,353,803.
A method and apparatus for supplying and controlling the flow of a liquid suspension through a laminar apparatus having separate parallel sedimentation spaces formed by plates inclined relative to the horizontal plane is shown in U.S. Pat. No. 3,794,167 of the type marketed by way of example under the trademark LAMELLA.RTM..
My process employs a liquid-solid separator which floats coagulated and flocculated particles by introducing air into a container below which light solids solutions flow so that the particulate matter rises to the surface on a blanket of air from which it is skimmed. The air may be introduced from a low pressure pump or by other means.
I use each of the above apparatuses in my mobile process making a new use of the old apparatus in a new process not taught nor suggested in the above patents as an anticipation of my claims to my new continuous mobile process. The equipment for practicing my process is mounted in mobile trailers which may be moved from site to site over the highway by tractors.
My process reduces both processing time and processing space required and is mobile and can be moved onto site and set up in a few hours. I treat the waste drilling fluids and then I relocate the mobile unit leaving the processed site ready for reuse and/or reclamation compatible with the environment.
My prior art search disclosed the following U.S. Pat. Nos.:
Cross et al (2,156,333) discloses a broad and general overview of cleaning oil well drilling fluids. Shown is refuse pit M, settling tank J, filter K, centrifuge L for generally liquid-solids separation. No chemical treatment as claimed herein appears to be disclosed, however.
Ohuchi et al (3,901,804) discloses a method for processing sludge showing a flocculator 2, a pH adjustment tank 12, and a solid separation tank 7 for the purpose of metal separation.
Johnson et al (4,200,526) discloses a waste water treatment process with pH adjustment, flocculating, filtering and reverse osmosis.
Crawford (3,777,405) discloses a drilling mud reclaiming apparatus which is portable and otherwise of general interest only.
Coillet (4,161,445) generally discloses brine/water separation by reverse osmosis process. The following U.S. Pat. Nos. are of general background interest:
3,350,301 PA1 3,577,341 PA1 3,664,440 PA1 4,001,114 PA1 4,350,596.